There’s an absence of data on teachers who cross the boundaries of acceptable discipline.

A Georgia science teacher is on administrative leave after a video surfaced that shows him threatening a student, ABC News reported.

The student’s outraged mother, April Carr, posted the video to Facebook on Friday. According to the news outlet, the incident began when a group of students at the Rockdale Career Academy in Conyers began laughing while their physics teacher wrote an equation on the board.

The teacher, who’s White, targeted Carr’s son, telling him that he will get in trouble.

“Don’t smile at me, man, OK? That’s how people like you get shot,” he tells the student who’s Black. “I got a bet. I bet by the time you’re 21, somebody’s gonna put a bullet right through your head. And it might be me — the one that does it.”

Carr said her son was not disrespectful to his teacher, identified in a police report as Paul Hagen. She called the incident “outright racist,” ABC reported.

Most research and statistics on classroom aggression focuses on students who threaten or physically assault teachers. Teacher aggression, however, often goes unreported.

Great Schools, a nonprofit that provides resources and information to parents, said teacher aggression targeted at a specific student can develop into bullying. It’s often “complex” to identify when an educator crosses the boundaries of acceptable discipline.

Part of the reason that teacher aggression goes unreported and unaddressed is that educators often rationalized their aggression, students at some point see it as normal, and it’s ignored by colleagues, according to Teaching Tolerance.